Compressed-air power plant.



APPLICATION FILED JUNE 5- l9l6.

H. P. J. E ARNSHAW. COMPRESSED AIR POWER PLANT.

2SHEETS-SHEET s.

Patented Jail. 28,1919. I

I H. P. 1. T IARNSHAW. COMPRESSED AIR POWER PLANT.

- APPLICATION FILED JUN E 5, 1916- r Patented Ja11.28,1919.

2 SHEETSSHEET 2.

river/fur I A f farms 1m: mum's "mu m. mmbuma. vllu'mhmiwl, II- c UNITEDSTATES PATENT OFFICE.

HENRY P. J. EARNSHAW, OF BOSTON, MASSACHUSETTS, ASSIGNOR T EARNSHAWMANUFACTURING COMPANY, INCORPORATED, 015 HARTFORD, CONNECTICUT, A

CORPORATION OF CONNECTICUT.

COMPRESSED-AIR POWER PLANT.

Specification of Letters Patent.

Patented Jan. 28, 1919.

Application filed June 5, 1916. Serial No. 101,708.

To all whom it may concern:

Be it known that I, HENRY P. J. EARN- SHAW, a citizen of the UnitedStates, residing at Boston, in the county of Suffolk and State ofMassachusetts, have invented certainnew and useful Improvements inCompressed-Air Power Plants, of which the following is a specification.

This invention relates to what I shall for convenience term a compressedair power plant the compressed air from the storage tank constituting apart of the apparatus, being usable for any desired purpose, butgenerally for effecting the action of a suitable tool. In machines ofthis nature, the air under compression is conducted from a compressor toa storage tank. When the compressed air enters the tank its temperatureis quite high. From causes familiar to those skilled in the art, the airas it passes along the tank is reduced in temperature, the reductioncontinuing as the air travels through the discharge duct or pipe'of thestorage tank and being so low that at certain seasons it freezes the oilof an implement which the compressed air from the discharge ductoperates. Various clumsy expedients have been adopted to overcome thisdifficulty, the one generally in vogue being the building of a fire toheat the air in the discharge duct or pipe. Besides thenatural'disadvantages following this procedure there is the added dangerof conflagrations. To prevent the compressed air at or in adj acence tothe tool being operated "from freezing the oil or the water, I providemeans preferably in constant relation with the said discharge *duct bywhich the air canbe heated before it reaches the tool to such an extentto prevent this-freezing. Thisparticular result can-be obtained in anydesirable manner, for exam- Qpleby a heatergove'rned by the motor foring part of thepresentspecification I have the air compressor. When saidair'compressoris operated by asteam engine as is the case inthe presentinstance, the exhaust steam; can be utilized for heating-the air in saiddischarge duct or .pipeto the requisite extent, or high pressure orboiler steam can be thus utilized.

In the drawings accompanying and formshown two of the several convenientforms of embodiment of the invention which I will setforth fully in thefollowing description.

I donot limit myself to this particular disclosure; I may departtherefrom in several particulars within the scope of the inventiondefined by the claim following said description.

Referring to said drawings:

Figure 1 is a top plan view of an apparatus involving my invention.

Fig. 2 is a side elevation of said apparatus.

Fig. 3 is a top plan view of the reheater showing a differentarrangement-of piping, the pipes being sectioned on the line 3-3 of Fig.4, looking in the direction of the arrow.

Fig. 4. is a vertical sectional view on the line 4.4 of Fig. 3, lookingin the direction of the arrow.

Fig. 5 is an end elevation of the reheater as seen from the left inFigs. 3 and 4, the pipe connections being omitted.

Fig. 6 is a transverse section on the line 6-6 of Fig. 3, looking in thedirection of the arrow, the pipe connections being omitted.

Like characters refer to like parts throughout the several views whichare on different scales.

I have alluded to the fact that I show two forms of the invention. Thereheater in both forms is the same, and in describing this it followsthat similar characters will be used to denote corresponding parts. Theprincipal difference between the showing of Figs. 1 and 2 and thatmadeby the remaining figures is in regard to the pipe connections aswill hereinafter appear. and 2 illustrate a reheater which is shown indetail in Figs. 3 to 6 inclusive.

Preferably, although not necessarily, the various parts of the apparatusare supported by a wheeled vehicle such as that denoted in a general wayby 2. The platform or deck of the vehicle sustains a storage tank as 3which can be supplied with compressed air by a compressor as'l, the pipe5 presenting a convenientmeans for conducting the compressed airf'romthe compressor to the tank. The compressor may be operated by anysuitable motor, for instance the compound steam engine 6 adapted to besupplied with the necessary steam in any desirable manner, for instanceby the pipe 7 leading from the steam space or dome of the boiler 8represented as carried by the rear of the ve hicl'e. It should be notedthat while a steam Figs. 1

engine as shown is the motor for effecting the action of a compressor as4, this may not in all cases be necessary. When, however,

a steam engine is utilized for this purpose,

the exhaust steam therefrom can be used to heat the air, or steam fromthe boiler can be utilized for this purpose. Boiler steam is, of courseunder high pressure while the exhaust steam is at a lower pressure, andit follows that when a boiler and steam engine are part of theequipment, either high or low pressure steam may be provided for heatingthe air.

Between the boiler 8 and the storage tank 3 there is disposed a watertank 9 connected in some suitable way with the water space of the boilerand which constitutes a convenient support for a reheater such as thatdenoted in a general way by 10 and shown 1n both Figs. 1 and 2. Thisreheater is the same as that illustrated in detail in Figs. 3 to 6, as Ihave already observed, so that it is obvious that if the reheater shown.in

the lastmentioned views be set forth in detail, this applies to thereheater 10 shown n Figs. 1 and 2. The reheater 10comprises in itsconstruction a casing as 11, having between its ends flanges or feet as12 adapted to be connected in some convenient rigid manner with thewater tank 9. One end of the elongated casing or housing 11 ispermanently closed, the other end being provided with a removable cap 13adapted to be held in place normally by suitable means as the bolts 14.As illustrated the casing 11 receives a plpe 15 of return bend orU-form, the branches of the pipe extending through and closelyfittingholes or perforations in the cap or plate 13, the bent portion ofthe plpe or heating member 15 being in prox-. mlty to the closed end ofthe housing or casmg 11. As represented there is a pipe connectlon(Figs. 1 and 2) 16 leading from the air storage tank 3, this beingconnected to what 18 shown as the upper branch of the heater 15, the airleaving the lower branch of said heater. In Fig. 4 the arrows 17 and 18show the direction of flow of the air, the air after leaving the heater15 being conductedby suitable meansto a pneumatic tool and being heatedwhile in the heater to such an extent that the air cannot freeze anyliquid that may be in the tool.

Referring now to Figs. 1* and 2, the numeral 19 denotes a pipe or ducconstituting sultable exhaust carrying 1116951. 1 for the gine 6. Fromthe pipe b tween the ends thereof, the branch pipe 20 exten there mg avalve, 21. at the junction inf the mainand branch pipes. in asteam-tight manner with thfi Casmg 11 of the reheater. There is connectewith sald casing 11 also in a steam-tight mn the branch pipe 22 whichhas a conneetion with the main pipe 19 back of the point of connectiontherewith of the branch pipe a b Thi i 20 i connected there being avalve 23 where the pipe 22 is united with the pipe 19. It will benoticed that the pipes 20 and 22 are connected with the casing 11 atlongitudinally spaced points, the pipe 20 being nearer the capped end ofthe casing than the pipe 22. The pipe 19 at its rear is provided withupwardly and downwardly extending branches 24 and 25, the branch 24opening into the stack 26 of the boiler, while the branch 25 opens to atm'osphere. At its rear end the pipe 19 is provided with a valve 27through which the exhaust can be directed at will into either thebranches 24 and 25. It will be clear that if the engine 6 be inoperation and that if both valves 21 and 23 be open, exhaust steam fromthe engine will pass from the pipe 19 into the branch 20 and from thelatter into the casing 11 circulating along the latter and leaving thesame by the branch 22. From this the exhaust passes again into the pipe19 and leaving the latter follows one of the branches 24 and 25,depending upon the position of the valve 27. If the exhaust steam entersthe branch 24, it is afterward exhausted into the stack 26 and then tothe atmosphere, whereas if it enters the branch 25, it goes directly toatmosphere. The exhaust steam entering the casing 11 effectually heatsthe air in the pipe 15 under ordi- 95 nary conditions. There may becases, however, such as in extremely cold weather where high pressuresteam is necessary for efiecting the desired heating of the air in theheater. For this purpose I have shown the pipe 28 extending from thewater columnv connection 29 of the boiler to the permanently closed endof the casing 11, this pipe being furnished with a valve 30 to admitboiler pressure steam as desired Leading from the casing to the waterspace of the boiler is the pipe 31 equipped with a valve 32 which can beopened to conduct the condensates into said casing to the water space ofthe boiler. I i I 110 Referring now to Figs. 3 to 6 inclusive,"

it will be understood that the pipes 28 and 31 and their adjuncts areshown in Fig. 3. Rising from the casing 11 near opposite ends thereofare the pipes 33 and 34 connected by the pipe 35, the pipe 36 connectedwith the pipe 33 between the casing 11 and the pipe 35 being provided toconduct exhaust steam from the engine 6. At the junction of the pipe 36with the pipe 33 is a valve 37 while in the pipe 34 is a valve 38. Whenit is desired to utilize the exhaust steam to heat the compressed air inthe pipe 15, the valves 37 and 38 are positioned as shown in Fig. 4, thecourse of the exhaust steam being indicated by the arrows. With theparts in this relation the steam passing from the pipe 36 enters thepipe 33 below the valve 37 then enters and travels along the'casing 11,passing therefrom into the 130 pipe 3 1, pipe 35 and then into the upperpart of the pipe 33 from which the said steam may be discharged into theatmosphere or otherwise disposed of. In said Fig. 3 arrows also show thecourse of the air into, from and then along the pipe or heater 15. Thevalve 37 can be moved to the dotted line position in Fig. 4 to divertthe exhaust away from the casing 11 and into the upper part of the pipe33. In this latter case the valve 38 will be closed as also shown bydotted lines in said Fig. 4. In the pipe 35 is a check valve 39 whichopens toward the left in Fig. &. In this view it is shown as Occupyingits open position by full lines and its closed position by dotted lines,being opened by the power of the exhause steam after the latter hasserved its function of heating the air in the pipe 15. If the valve 37be moved to the dotted line position in said Fig. 4 and the valve 38also closed, the steam will move the check valve 39 to closed positionand thus prevent the steam from entering the casing 11. It may be in thelatter case that the valve 30 will be opened so as to supply boilerpressure steam into the casing 11, and in this particular conditionexhaust steam may not be utilized. As a matter of fact there may becases such as in excessively warm weather or even moderately warm or inindoor work that it may not be necessary to have recourse to the steam.

When the engine 6 is in operation, it will be clear that it operates thecompressor 4, and the latter in turn supplies compressed air to the tank3 which passing therefrom by way of the pipe 16 enters the upper branchof the return bend pipe 15 and leaves the lower branch thereof asalready noted,

being conducted by suitable piping or other wise to a proper tool orconveniently utilized for the intended purpose. If necessary the air inthe pipe 15 can be heated by steam in either of the ways already setforth. 'As will be obvious I do not restrict myself to the heating ofthe air in this particular manner, for the purpose can be accomplishedwith equal advantage in other fashions.

It will be apparent that the return bend pipe 15 which I have describedas a heater is actually such, or at least a part of a reheater. In thepresent case it constitutes also a part of the discharge piping for thecompressed air of the storage tank.

What I claim is:

In an apparatus of the class described, the combination of a compressedair storage tank and a discharge pipe therefor, said discharge pipehaving a return bend, a casing receiving said return bend, a steamboiler, an engine operated by the steam. from the boiler, an aircompressor for supplying compressed air to said tank and operated bysaid steam engine, a pipe extending from said casing at one end thereofand having a valve, a second pipe extending from the easing near theopposite end thereof and also having a valve, a connecting pipe unitingthe other pipes at a point outward beyond the valves therein and havinga check valve, and a pipe for conducting exhaust steam from the engineto the first mentioned pipe at the point where the valve is locatedthere- 1n.

In testimony whereof I aflix my signature in the presence of twowitnesses.

HENRY P. J. EARNSI-IAW.

l/Vitnesses L. L. MARKEL, HEATH SUTI-IERLAND.

Copies 01' this patent may be obtained for five cents each, byaddressing the Commissioner of Baton, Washington, I). 0.

